It has a thick skin rougher than peel (8)
I believe the answer is:
elephant
'it has a thick skin' is the definition.
The definition suggests a singular noun which matches the answer.
'rougher than peel' is the wordplay.
'rougher' indicates anagramming the letters (I've seen 'rough' mean this (a rough or broken ordering of the letters)).
'than'+'peel'='thanpeel'
'thanpeel' with letters rearranged gives 'ELEPHANT'.
Can you help me to learn more?
(Other definitions for elephant that I've seen before include "Large animal found in the plane?" , "Large pachyderm" , "Get this animal from Pat and Helen" , "Huge African or Indian animal" , "Size of paper" .)